Two types of superconducting wires: a superconducting wire using a bismuth-based superconductor and a superconducting wire using an RE123-based superconductor are now being particularly developed. Of these wires, the RE123-based superconducting wire has the advantage that the critical current density at the liquid nitrogen temperature (77.3 K) is higher than that of the bismuth-based superconducting wire. Additionally, it has the advantage of a high critical current value under a low temperature condition and under a certain magnetic field condition. Therefore, the RE123-based superconducting wire is expected as a next generation high-temperature superconducting wire.
Unlike the bismuth-based superconductor, the RE123-based superconductor cannot be covered with a silver sheath. Therefore, the RE123-based superconductor is manufactured by depositing a film of a superconductor (superconducting thin film material) on a textured metal substrate by a vapor phase method only or a liquid phase method only.
Japanese Patent Laying-Open No. 2003-323822 (Patent Document 1) for example discloses a method of manufacturing a conventional RE123-based superconducting thin film material. Patent Document 1 discloses the technique of forming an intermediate layer on a metal tape substrate using the pulsed laser deposition (PLD) method, forming a first superconducting layer having an RE123 composition on the intermediate layer using the PLD method, and forming a second superconducting layer having an RE123 composition on the first superconducting layer using the pulsed laser deposition method.    Patent Document 1: Japanese Patent Laying-Open No. 2003-323822